Mechanism of touchscreen

Answer 1

There are three different systems used in the mechanism of touch screen.

1. Resistive System

In this resistive mechanism of touch screen two sheets are used one is conductive and the other is resistive. Both cover the top glass panel. There is a space between two sheets so that current pass when it is toggle. Now touching the screen forced both layers to contact at a certain point. This contact of both layers cause in the electric field a variation which is informed to the main system that a touch is felt. OS transcribe the touch into desired action.

2. Capacitive System

Second method utilizes in touch screen is capacitive. To understand this mechanism, it is better to know about human Biology first. Many chemical reactions take place in our body and electricity produced in result to perform different functions. That is the reason why human heart is recharged with electric shocks for the recovery. Considering human body a cell you can better understand this phenomenon. In this system an electric charge sheet (capacitor) is directly placed on the glass. When we touch the screen with finger, a static charge produces and reacts with the capacitor (electric charge sheet). As the touch screen works due to electric current develop when touches the finger.

3. Surface Acoustic Wave System

This type of touch screen works with the help of wave energy. This enables a touch to transform into another form of energy and deliver the command which in response perform the desired action. A pair of transducers is placed on glass plate sides. In the glass plate there are reflectors. On touching the screen wave produced and which transforms into energy for fulfilling the command. It tells where on the screen touch is detected.

Important Information

First both techniques utilize the electric charge mechanism to develop a touch screen system but the third uses wave system and do not need a metallic plate. This surface acoustic wave system is free of electric field that's why there is no resistance in the way of light dispersal. This 100 percent light emission gives extra clarity to the screen which is not possible in first two mechanisms. Resistive system enables 75 % of light emission. However capacitive system allows 90% of light emission so better than resistive. Capacitive system enables sharp image as compared to resistive system even then no comparison with the image quality if surface acoustic system.